Hands-On Design Patterns with React Native

Issues with duplicated data

The task list component fetches the data necessary to display the list on its successful mounting. However, there is no mechanism implemented to prevent duplication of data. This book is not meant to provide recipes for common problems. However, let's think of a few solutions you could implement:

• Change the API and rely on unique task identifiers (such as ID, UUID, or GUID). Make sure you filter to only allow unique ones.
• Clear data on every request. This is good; however, in our case we would lose unsaved (API-related) tasks.
• Maintain status, and only request once. This would work in our simple use case only. In more complex apps, you will need to update data more often.

Okay, bearing this in mind, let's finally ...